ASE A5 Brakes Practice Test
31. After replacing all four rotors and pads on a disc brake system, a pulsation is still felt in the steering wheel when braking. Which of the following is MOST likely causing this vibration?
- A. A rusty hub flange.
- B. Sticking slide pins.
- C. Thickness variation.
- D. Lateral runout.
Answer A is correct. Rust and debris result in an uneven surface on the hub flange.
Answer B is wrong. Sticking slide pins cause uneven pad wear.
Answer C is wrong. Since it has four new rotors; it is most likely something else, like the hub flange.
Answer D is wrong. Excessive lateral runout will cause a vibration in the steering wheel. The importance of inspecting components like the hub flange can not be understated. Rust or debris on the flange results in a comeback with a pulsation that occurs when braking.
32. A vehicle has a soft and spongy brake pedal at all times. Which of the following is causing this spongy pedal?
- A. Air in the brake lines.
- B. Low manifold vacuum.
- C. The brake booster.
- D. Master cylinder cup seals.
Answer A is correct. Air bubbles in the brake lines result in a soft spongy pedal.
Answer B is wrong. A low manifold vacuum would deprive the vacuum assist unit of its vacuum source.
Answer C is wrong. A faulty vacuum booster results in a hard brake pedal.
Answer D is wrong. Leaking master cylinder cup seals cause the brake pedal to fade to the floor.
33. A vehicle with a front disc rear drum brake system nosedives while lightly braking. Which of the following is causing this condition?
- A. Worn brake pads.
- B. Over-adjusted brakes.
- C. The proportioning valve.
- D. The metering valve.
Answer A is wrong. Worn brake pads result in brake squeal.
Answer B is wrong. Over-adjusted brakes result in brake drag and worn rear brake shoes.
Answer C is wrong. The proportioning valve prevents rear wheel lockup.
Answer D is correct. A faulty metering valve results in a nosedive condition.
34. A vehicle has a grinding noise that gets louder and changes in pitch while turning left. Which of the following is causing this noise?
- A. A cupped left front tire.
- B. A faulty right front wheel bearing.
- C. A grabbing left front brake.
- D. Worn left front strut.
Answer A is wrong. A cupped left front tire results in a noise that changes in pitch on different road surfaces.
Answer B is correct. Bearings make a grinding or growling noise that changes pitch during turns. The bearing on the outside of the turn is worked harder and is loudest because it has more of the vehicle's weight leaning on it.
Answer C is wrong. Left front brake drag causes the vehicle to pull to the left.
Answer D is wrong. Worn struts result in cupped tires.
35. The master cylinder reservoir cap gasket is swollen and deformed. The cap fits tight, and there are no external leaks found. Technician A says the brake fluid is contaminated. Technician B says brake fluid is hygroscopic and readily absorbs moisture from the air. Who is correct?
- A. Technician A
- B. Technician B
- C. Both A and B
- D. Neither A or B
Answer A is wrong. Petroleum products are particularly damaging to rubber brake components. Inspect the gasket for damage and the fluid for contamination. If the gasket's seal is missing or broken and the brake fluid is contaminated, a flush will be necessary.
Answer B is wrong. Brake fluid is hygroscopic and readily absorbs moisture from the air. The reservoir cap gasket functions as a flexible seal to prevent contamination of the brake fluid. Fluid would appear on the reservoir's body if the cap seal were leaking.
Answer C is correct. Most of today's vehicles have composite plastic reservoirs with a screw-on type cap. Reservoir caps have a rubber gasket between the cap and the reservoir.
Answer D is wrong. The gasket flexes inward and prevents air from entering the system as reservoir levels drop.